U.S. cities that refuse to step up efforts to focus on crimes committed by undocumented immigrants will not be allowed to participate in a new crime reduction training program the Justice Department unveiled this year, Attorney General Jeff Sessions said Thursday.

In making the announcement, Sessions singled out four local police departments that had expressed interest in the new Public Safety Partnership Program, saying they first had to answer a list of questions by August 18 confirming they did not have any "sanctuary" policies to shield illegal immigrants from possible deportation by ensuring they would allow federal immigration officials access to local jails.

"By protecting criminals from immigration enforcement, cities and states with so-called 'sanctuary' policies make all of us less safe," Sessions said.

The four police departments that must respond are Albuquerque, New Mexico; Baltimore, Maryland; and San Bernardino and Stockton, California.

Representatives from the police departments did not immediately respond to requests for comment.

Sessions' announcement reflects part of a broader policy push by President Donald Trump to crack down generally on illegal immigration.

He has urged Congress to support funding the building of a wall along the U.S.-Mexico border, and the administration has moved to dramatically widen the group of illegal immigrants targeted for deportation.

High-crime areas

The National Public Safety Partnership is a new program launched in June that involves a three-year initiative geared toward areas with high rates of violent crime.

Twelve cities were selected when it was launched, including Buffalo, New York, Houston, Texas, and in Sessions' home state, Birmingham, Alabama.

It is unclear how cities with interest in the program may respond to the Justice Department's stance, but some municipalities have pushed back against the Trump administration's immigration policies.

A U.S. judge last month refused to remove a block on an executive order by Trump that would have withheld federal funds from sanctuary cities, which do not use municipal funds or resources to help advance the enforcement of federal immigration laws.

New York Attorney General Eric Schneiderman and Acting Brooklyn District Attorney Eric Gonzalez on Thursday called on U.S. Immigration and Customs Enforcement (ICE) to stop making arrests in courthouses amid concerns it has a chilling effect on local policing and is sweeping up those with low-level misdemeanor cases.

Rachael Yong Yow, a spokeswoman for ICE in New York, said the agency's arrests are carried out "on a case-by-case basis."